Jenny outputs three files in the DTO, DAL and BLL.
These files are then compliled with your application.

The real advantage of using Frictionless Data is when you come to write your application code.
The toolset handles writes too, but most of your data accesses will be reads.
Jenny exposes three core "Fetch" methods for each of your tables:
FetchAll, FetchOne and FetchZoo ( Zero Or One rows ).